The compound having the formula (X-1) has been disclosed in WO 01/47919.

It is also known as rivaroxaban and is marketed in a number of countries under the trade designation Xarelto®.
The compound having the formula (X-1) acts as an inhibitor of clotting factor Xa and may be used as an agent for the prophylaxis and/or treatment of thromboembolic disorders, especially myocardial infarction, angina pectoris (including unstable angina), reocclusions and restenoses after angioplasty or aortocoronary bypass, stroke, transient ischemic attacks, peripheral arterial occlusive diseases, pulmonary embolisms or deep venous thromboses.
One method for preparing the compound having the formula (X-1) is disclosed in WO 2004/060887.
A further known compound has the formula (X-2)
which is referred to as linezolid and is commerically available under the trade designation Zyvoxid®. It is useful as an antibiotic for treating infections caused by Gram-positive bacteria because it functions as a protein synthesis inhibitor.
EP-A-515 272 describes chiral sulfates and their use in the preparation of pharmaceuticals.
WO 01/047919 discloses substituted oxazolidinones and their use in the field of blood coagulation.
It was an object of the present invention to provide a simple and cost-effective method of preparing a compound having the formula (X). The present method is advantageous because it can use less expensive starting materials, such as (S)-3-chloro-1,2-propanediol. Furthermore, it has the option of performing several steps of the synthesis as a one-pot process which reduces the number of isolation steps. The synthesis of the compound having the formula (IV) can be performed as a one-pot reaction starting, e.g., from (S)-3-chloro-1,2-propanediol. Also the synthesis of the compound having the formula (VIII) can be performed as a one-pot reaction starting from the compound having the formula (IV).